There I Ruined It only uses AI to change his voice so it sounds like the artist he's parodying (and a small amount of auto-tune) -- 99% of the vocal performance real human singing.
The video's maker claims this is parody but seems more like just (at best) satire which receives less legal protections typically. It doesn't seem that there's any commentary on the work original IPs, given the rest of his body of work.
It's a composition in the style of Johnny Cash that's meant to be funny. That's parody.
That's satire. In the US for something to be parody it has to be a commentary on the original work(s) or author(s). A parody of Johnny Cash would be something like if they used AI to copy his song note for note but had lyrics that criticized him for portraying himself as bluecollar in his music despite his wealth.
Parody receives higher protection than satire because the parodist is actually trying to make a statement. Most "music parody" like that of Weird Al is satire, which is why Weird Al asks for permission from the original artists.